In the art of making and using toner powders, charge control agents are commonly employed to adjust and regulate the triboelectric charging capacity and/or the electrical conductivity characteristics thereof. Many different charge control agents are known which have been incorporated into various binder polymers known for use in toner powders. However, the need for new and improved toner powders that will perform in new and improved copying equipment has resulted in continuing research and development efforts to discover new and improved charge control agents.
Of potential interest are substances which not only serve as toner powder charge control agents, but also function as agents that provide additional results or effects. Such multi-functionality not only offers the potential for achieving cost savings in the manufacture and use of toner powders but also offers the potential for achieving toner powders with performance capabilities not heretofore known.
Charge control agents that contain either incorporated ester groups or incorporated quaternary ammonium salt groups are known ("Research Disclosure No. 21030" Volume 250, October, 1981, published by Industrial Opportunities, Ltd., Homerville, Havant, Hampshire, P091EF, United Kingdom) but charge control agents that contain both ester groups and quaternary ammonium groups in the same molecule are unknown, so far as now known.